#!/usr/bin/env python

# Copyright 2011 Google Inc. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#    http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""Each method execution is recored in the DB."""

from lib.loggable import loggable
import model

__author__ = "Maciej Machulak"
__maintainer__ = "Maciej Machulak"
__email__ = "mmachulak@google.com"

__copyright__ = "Copyright 2011, Google Inc."
__license__ = "Apache License 2.0"
__version__ = "0.1"
__status__ = "Prototype"

def billable(method = None):

  def inner_billable(handler):

    @loggable      
    def bill(self,*args):
       
      if method is None:
        raise BillableError('method name not set')      
      bill_history = model.BillHistory(
                application = self.application)
      bill_history.put()
    
    return bill
  
  return inner_billable

class BillableError(Exception):
  
    """Raised when the method for which billing should be provided does not exist."""
    def __init__(self, msg):
        Exception.__init__(self)
        self.msg = msg

    def __str__(self):
        return repr(self.msg) 

if __name__ == '__main__':
    pass  